\chapter{Acknowledgments}

I would like to take this opportunity to express my gratitude to all the people who have given me help, advice, and suggestion. 

Firstly, I would like to thank my supervisor, Associate Professor Lim Tiong Wee, for all the guidance, support, and encouragement. During the two years of study under Prof. Lim's guidance, he has taught me a lot about research as well as English. I was lucky to have him as my supervisor. 

Secondly, I would like to thank my husband Ma Jia Jun for his love and company. He has making me feel home in this foreign country. I am also grateful to all my friends for their encouragement and care, and for the great memory we share. 

Lastly, I would like to acknowledge the Department of Statistics and Applied Probability for providing us a friendly research environment. 


